


canens umbrarum

by The_Amarathine_Carrion



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Blood Drinking, Dirty Talk, Double Penetration, Established Relationship, Felix is ambiguous when it comes to human gender but uses He/Him pronouns, Incubus Sylvain, M/M, Monsterfucking, Multiple Orgasms, Pet Names, Possessive Sylvain, Praise Kink, Shapeshifting, Vaginal Sex, vampire felix
Language: English
Status: Completed
Published: 2020-05-17
Updated: 2020-05-17
Packaged: 2021-03-03 05:47:38
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,544
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24239785
Author URL: https://archiveofourown.org/users/The_Amarathine_Carrion/pseuds/The_Amarathine_Carrion
Summary: Felix and Sylvain have maintained a mutual exchange of services for centuries.Sylvain wants more.
Relationships: Felix Hugo Fraldarius/Sylvain Jose Gautier
Comments: 8
Kudos: 124





	canens umbrarum

**Author's Note:**

  * For [Jess_B_Fossil](https://archiveofourown.org/users/Jess_B_Fossil/gifts).



> For Jess, who deserves an eternity of Sylvain doting on his grumpy Vampire. ❤️
> 
> Title is lifted from a line in my one of my favorite Eric Whitacre pieces, Nox Arumque: https://youtu.be/GIiiTjEQjxw

Before Sylvain even thinks to step out onto the curb that night, he already knows the fate that awaits him. 

It’s cold. He’s thirsty and tired. The fog that seems to swirl ahead without end is thick enough to be felt, like an extra layer of skin. There’s no reason for him not to take an Uber or call a cab. 

There’s no reason for him not to walk home either. He only ordered two drinks: one so he could nurse the warmth of the bar for as long as he dared to stay, and one for the road. He’s perfectly capable of defending himself from anyone who considers him a target, but his broad chest, muscled arms and sturdy legs usually deter the situation from arising. Besides, it isn’t _too_ late yet— there’s still the smell of exhaust from the cars carrying those unfortunate enough to work the graveyard shift. The streetlights above are just as bright as their unblinking, northbound eyes. 

Sylvain knows what he is tempting. He can hardly contain how badly he wants it to come.

Even so, he sets to the sidewalk like he’s in no hurry. He allows the emotions that welled up within him over his whiskey (neat— it takes too long otherwise and the ice ruins the taste) to occupy his mind as he goes. There’s not much else around him to take in but the buzz of technology, still blaring through the sealed windows, and the murmur of strangers preparing for bed— lovers, families, friends, he hears it all. The city is never truly quiet. It sleeps with all of the submission of a wild cornered animal, muzzled and bound, still seeking freedom and biding it’s time until the perfect moment arrives to snap the cord and claw at your heart.

It reminds him of his love. That’s why he’s stayed here longer than any other place he’s frequented. It’s been years since they’ve last met. Felix will come, though. Sylvain is sure of it.

He’s here already, out of sight— not a single sound that their sensitive ears could hone in on, but Sylvain can still tell. There is a connection between them that ties across the gaps where lesser perception fails. It’s nothing creatures born of this world would know about. 

He turns another corner and strays from his path. Sylvain flings the bottle into the first trash can he finds, tucked a few paces away from the misty gloaming where no lamps are erected. His eyes fix far off into the distance of that void, tracking a different source of light.

“Come on out from over there. Let me see you.”

A muffled hissing meets his ears. Sylvain chuckles at Felix’s choice of manifestation and leans against the narrow walls of the alleyway. Under the starless veil, their color resembles a handsome, red-tanned leather, rather than the crumbled brick he knows it to be. 

Amber slits, small and sharp, shine from the depths of the darkness. “How long have you known I was following you?”

Sylvain shrugs, easy and honest. “Hard to say. I’ve never understood the way humans organize their concept of time. You know I don’t own a calendar.” 

Felix’s silence is a response in its own category— heavier than many of his other insults. Sylvain whistles lowly to cover it when he realizes he’s already ruining the moment. His love is in no mood to banter right now, apparently. He must be just as ravenous as he is, then. 

“Oh. You were talking about tonight.” 

A deep grumbling is all he’s given to work with. Felix is trying to drag him out there, rather than approach him like they both know he’s dying to do, but Sylvain is more than comfortable to remain here until he gives in. It’s been a while, after all, and he wants to savor every moment of their tension before it snaps beyond the point of no return.

Felix always finds him on nights like this. Sylvain has never thought to ask why. He can sense the coming of their tryst when the moon is vivid and full and low in the sky. The proximity could give him a boost to his transformative powers, maybe— he’s not too certain where that limit lies. Then again, it could be something as simple as the pretense of mystery. Felix does enjoy remaining hidden until he’s well and ready to pounce and claim his prize.

They both enjoy that particular activity. It’s an essential element of their agreement.

Sylvain clucks in a false disappointment. “Don’t be like that. You know it’s nothing personal. I can’t forget the lifeblood of anyone I taste.”

The taste of Felix has graced his lips so many times by now Sylvain feels as if they are never truly separated. It doesn’t matter what form Felix takes. It’s impossible, when you’re weighed down with wanting, to conceal yourself from an Incubus. Sylvain could pick out his specific vitality from an endless line of clones. Everyone else has merely served him as a sea of identical faces— meaningless, save for one purpose. He feeds, and casts them away, leaving them to drown in their misery alongside the rest of human society. He feeds, but never drinks his fill, yearning for this moment with an unprecedented patience concerning his kind.

“I know.” 

The voice sounds closer— a little warmer. Soft clicking reverberates on the raised stones that fail to cushion anything beneath their feet. They’re in an older part of town. It’s beyond the budget of the legislation to keep up with modern appearances _or_ comforts. There’s no one to impress here. There’s no one who’d bother sticking their neck out to come and see.

The clicking resounds—nails, he’s certain now—accompanied by a mild warning. 

“I’m conserving energy in this form. It’s good camouflage. Don’t you dare mention it.” 

Sylvain straightens and steps forward slightly in response, eager to see what he has to work with.

At first, the eyes are all he can make out. He’d kept them in his line of focus, stupefied by their hunger, as always. Shadows ripple around them as they advance, becoming more and more diminutive until they narrow into a sleek, shining feline crouching by the ground. Sylvain grins, wide as can be, and bends to pat his head. 

“Cute.”

He pulls back just in time to avoid the furious swipe of a paw. Felix growls at him, ears flattened and tiny fangs gleaming with a threat that surpasses the capabilities of his current physiology.

“I’ll eviscerate you.”

Sylvain ignores the promise, because common sense has never been his strong suit, and picks him up. He laughs as Felix struggles to gain footing, lifting the miniature midnight menace high into the air like it’s his turn to play Lion King in the circle of show and tell. 

He presses his dwindling luck even further by placing a kiss on the black velvet nose. “Oh, I don’t doubt it. Not in that state, though.”

There’s a blinding flash of white light, and before he knows it, Sylvain is slammed against the harsh bricks. The stones jutting from years of disrepair—and likely some gang-related activities—bruise his back. He groans at the intrusion of an unfamiliar body pinning him there, raising his wrists above his head and scoffing through the hot, angry, breath mere inches from his own slackened mouth. 

“How about now?” 

Sylvain coughs out a laugh. It comes in short spurts that die off as quickly as they spark. The constriction of curves tether him in all the right places, and _oh, how he has missed this._ Sylvain closes his eyes for a second that feels like an eternity, to savor the feeling of it. Lips are quick to attack him, teeth relentlessly nipping until he’s clearly announcing his arousal. His mouth is still warm from the whiskey, but Felix’s tongue has something additional to give. Liquor never could imitate the heat of a lover. A lover never could imitate the inferno that is Felix.

Felix lets one hand fall, snarling as he pushes harder into him, pulling at his hair, arching like he wants to lift him up and take him right there. It wouldn’t be the first time. Sylvain isn’t picky about how and where they fuck. He gets what he’s after, in the end.

Satisfying his partner is important; there’s nothing worse than the taste of soured sex. It’s never something he worries about with Felix. Their mutual exchange of services was the best proposition he’d received in the thousands of years he’s spent striking deals with all manners of beings.

The temperament of his love is strident, like bitter citrus peels and the tang of rusted iron, but his center is soft. Sylvain dips his hands into that pool of honey with every passing sigh and breathy twitch. 

Felix felt even softer tonight. His alabaster skin was unearthly pale as if emitting its own luster. His moans were lighter, pitched higher, greater in frequency than Sylvain had come to expect. He reaches between their chins as they continue to grapple for dominance and wraps a hand around his thin, smooth, neck, causing Felix to gasp and rut forward, firmly falling into his chest.

Well, there’s something new.

“Gotta say, Felix— I never imagined you with a pair of tits before. I should have started doing it a _long_ time ago.”

Pinpricks of pain flash across his collarbone only to disappear under the swipe of a tongue in the following moment. Felix licks a dribble of blood off of his lip in an act that would be far more intimidating, if not for the dark, wide-blown rings of his eyes. 

“Shut up. You’re incorrigible.” 

Sylvain’s eyes narrow in tandem with the heat burning at the tips of his elongated ears. “You have no idea.”

Felix’s blush is something he cannot hide, even in the dim alleyway, because Sylvain can feel it. It’s feeding him, making him stronger, bolder— giving him more urges than what they have time for. He wants to hold Felix’s cheek to the side with his palm and bite down on _his_ neck next, draining him of the energy necessary to complete the ritual. He knows Felix will turn his face away anyway, dark as it is, because regardless of how aggressively he initiates, he’s bashful over his compliance once Sylvain takes charge.

“I have some idea.” Felix counters. “You’ve shown me before.”

True, Sylvain had shown him more of what an Incubus could do for their partner than anyone he’d previously been with. However, all of those encounters had featured a Felix that was flat chested, more angular, with lithe muscles that writhed underneath his command. Felix’s tight hole, his pretty cock, weeping for attention, suited him perfectly— Sylvain would never tire of wanting it. Yet, the excitement of a new territory to explore in the one he most adores was too much of a temptation for him to bear.

Without hesitation, he dips his hand between Felix’s bare thighs, prying them apart, and lightly presses two fingers low into the impression of the dampened fabric over the mound he’s pleased to discover is, in fact, there. 

Felix’s breath hitches— the softest whine barely audible beyond the pounding of Sylvain’s heart in his head. _Fuck_. This is going to drive him to madness.

He presses a kiss to the side of his temple, increasing the pressure and relishing how the higher pitch of Felix’s small moan resonates when it comes. 

“Oh, _Sweetheart_. There’s so much more to see— so much pleasure you don’t know about.”

Felix bites down on his lip, keening as he cannot prevent himself from sliding against those fingers, slick coating the pads when Sylvain pushes the fabric to the side to delve deeper. It’s downright _gorgeous—_ he has no right to look this enticing already. They’ve waited a long time to feast upon one another, but Sylvain’s hardly started. 

“Darling— you’re _dripping_.” 

Together, the fingers slip up into his waiting heat. Felix gasps, tensing around them while he locks his wrist behind Sylvain’s neck and flops his head onto his shoulder like all of the strength to stand has left him. It’s not too far off of an assumption. Sylvain’s ruddy tail rips through the seat of his pants and extends behind him. It whips against the wall and creates even more gashes to avoid, sending dust and loose rubble crumbling around them. He’s starting to lose control of his transformation— it’s been held at bay for too long. 

Okay, damage control. What Felix was doing to him right now was _dangerous_. He needs to move them to a safer location. He needs to lay him down properly and bury more than two measly fingers inside.

Another kiss is pressed to the crown of his head as Sylvain slips his fingers free and sweeps Felix off his feet, cradling him bridal style against his chest. Felix groans, offended on both accounts. He wraps a fist in the fabric of Sylvain’s shirt—intending to mouth off, certainly—but the Incubus doesn’t allow it, already twisting in the darkness. 

“Hang on tight, Sweet.”

Both of them need a few seconds recovery as they blink their way back to awareness. Teleportation is a tricky thing even while he’s fully transformed, and more so with another soul accompanying him. Yet, with the amount of raw energy flowing from Felix’s body into his own, Sylvain was confident he could pull it off.

Besides, it was necessary. He couldn’t leave Felix waiting. 

Here in his room he’s able to gather his focus— smell the sweet scent Felix emits as he breathes shallowly, breasts rising and falling between the arms wrapped around his neck. His eyes are heavy and unfocused, shining with a combination of desire and exhaustion. It’s a lovely look, albeit a bit concerning. Sylvain lays him down on the edge of the bed, sliding his thighs apart and fitting his body between them— leaning forward to stroke the side of his bloodless face. 

“ _Oh, Fe._ You waited too long again.”

Felix manages to scoff in between his slow, labored breathing. He grabs at the hand cradling his cheek and squeezes. Weakness doesn’t suit him, Sylvain can sympathize, but he’s come to him in this state before, because for reasons they both know and Felix won’t admit, he’d refused to feed from anyone but Sylvain.

“What of it? You’re here now.” 

Sylvain smiles, dipping his thumb past Felix’s chapped lips and rubbing ever so gently against the sharp canines there. Felix moans in appreciation, but doesn’t bear down, letting him tease inside of his mouth until saliva is leaking from the corners. His thighs tremble, locking Sylvain into place. Sylvain’s free hand pushes the soft velvet fabric of Felix’s black dress up until he’s running his fingers over his slim waist. 

“I am. Shall I take care of you?” 

The thighs around him tighten even more as Felix pants dizzily, arching and mumbling a quiet curse as a response. Sylvain’s thumb finds his clit and plays with it, rubbing in soft teases— pleased to feel how soaked the thin fabric that is the only thing separating him from Felix’s new hole is. He yanks at the obstruction, nails extending to carefully draw a slit down the front so he can slide his fingers though the wetness of his folds again. Felix is clenching already, though there’s nothing inside yet, and Sylvain’s cock aches to be buried deep inside of the pulsing heat.

Sylvain growls, eyes blazing as the rings of rust bleed into embers of red. Everything Felix is wearing irritates him, keeping their bodies from burning together. He tugs at the black lace, trying to get it off without disturbing the space Felix insists on filling with as much of his body as possible. It’s entirely ruined from his claws, hanging uselessly off of one thigh. He cuts through the rest of the strings like air, letting the tattered remains fall where they naturally go, hiking Felix’s leg up to expose him further.

He stops and just looks at Felix. There’s blood dribbling down his bottom lip from all the little bites when he whimpered, pussy glistening and swollen— leaking at the slit and beginning to stain the sheets. His hair is a disheveled mess already, loose as he normally keeps it. Sylvain pushes the half knotted bun to the side, intending to watch it continue to unravel when he finally decides to pound into him.

Felix’s eyes snap to him at the action, grunting in impatience.

“Moron— did you forget you’re an Incubus? Hurry up and fuck me.”

Sylvain’s horned ears perk up at the request, but he retracts, pushing Felix’s face to the side and moving dampened fingers to the base of his skull. He pulls just enough at Felix’s hair there to bring a shocked, pleasured, gasp from him— because he won’t prioritize anything else over reminding Felix who’s in charge whenever Felix decides to be a bratty little shit.

“This is how I want to see you right now. You know I’ll give you exactly what you want—what you need— ”

“So give it then.” Felix interrupts, challenging even through the stupor of arousal and malnutrition. “Why do you insist— ”

He cuts off with a cry when Sylvain yanks at the bun sharply. What a rebellious kitten. He’s not even close to being capable of deceiving anyone about his true desires. Sylvain loves it though, taming the desperate beast within— the process of breaking him. 

“Beg me.”

Felix’s eyes pop, looking furious at the request. It’s been a long time since Sylvain has pushed him so far, but _damn_ did he need to hear him say it tonight. 

“I’ll do no such— ”

Sylvain’s tail extends again, curling around his thigh and sending Felix into a full-bodied shiver. He presses the fingers that are not laced into Felix’s hair into his hip bone, gripping hard as the slender, warm, appendage strokes its way up Felix’s body until the barbed tip finds its way comfortably flicking against the underside of his chin. Felix mewls— his twitching ears at full attention. Sylvain rubs his lips against them, humming in pleasure, savoring the way the soft velvet feels. 

“There we are, my sweet. _My darling kitten._ Give yourself up to me.” 

Felix shuts his eyes hard, slackening his muscles as he focuses on breathing deeper and slower. He’s still paler than Sylvain would like to see, but the anxious tension that gripped Felix from the moment he’d slunk up to him in the alleyway was fading. It wouldn’t take too much longer for Sylvain to finish gathering the energy he needs. He did plan to burn through it multiple times over once Felix had his turn, however. They had all night, after all. 

Sylvain pries Felix’s mouth open wider with the two fingers that were still wet with his juices, giving him a taste while his tail continues to tease around his body. It’s smooth and pliable, longer than his legs— the color a carbon copy of his hair. Felix tries not to writhe as the barbed end drags into his navel when the tail curves around his waist. It continues, wrapping around a thigh and pulling it back further, allowing Sylvain to shift to move in deeper against him.

“Tell me you want me, clawing at your back— claiming you. You’re mine, Felix. Mine to play with. I’m going to destroy you, and you’ll enjoy every second of it.” 

Felix swallows, running a hand down his chest to pinch at his nipples. “Sylvain— ”

“That’s it, baby. Touch yourself like that. They’ve never felt so sensitive, have they? Explore yourself while I teach you just how deep inside of you I can go.”

He leans forward, tilting Felix’s face back by running his fingers through the hair on both sides of his head, finally kissing him as he’s wanted to this entire time. Felix immediately opens to receive him, his tongue flowering as if rubbing it on the inside of Sylvain’s mouth was more important than any subsequent breath. It’s no secret that all Vampires have an oral fixation. Felix might not be exactly like the rest of his kind, but he’d still happily spend the majority of the night just bruising their lips. 

It’s a fine way for Sylvain to feed, usually— it just takes longer. 

The whimpers Felix leaves against his lips are like little drops of rain after days wandering deliriously through a desert. He feels Felix’s fingers trembling as they claw at his chest underneath them, breasts exposed by the thin straps of his flimsy dress edging down the sides of his shoulders.

Sylvain hums, lifting his body and swinging over the side of the thigh that isn’t shaking violently in the constriction of his tail. It loosens slightly, snaking further up until the tip is rubbing between Felix’s swollen slit, causing him to choke. Sylvain shushes him, pulling his mouth back and swallowing the strand of saliva that connects them. He rubs his fingers over Felix’s bare breasts gently, noting the goosebumps and chuckling. Felix’s small, tight dress is comically bunched up beneath his chest and above his navel. It’s gone from a vision to an eyesore. There’s no need for it anymore. 

At the same time that he rips the rest of Felix’s dress apart with his pointed nails, the tip slips inside Felix’s heat and catches there. 

Felix arches into it, surprise magnifying his features. His nails extend, despite his weakened state, and draw blood when he digs them into Sylvain’s arms. Little exhales of _ah—ah—ah—_ encircle the otherwise silent pair as they adjust to the pulsing of their energy, now genuinely entwined.

“ _Fe…_ you feel— ”

He feels like heaven— is what a human would probably say, but Sylvain’s never been there and he doesn’t particularly hold any interest in changing that. It’s so much better here, nestled deep and warm and tight into the only place he’d consider worshipping if even a single cell within him was capable of it.

Felix whines distressingly, drawing blood from his lip again that Sylvain wipes away with a finger and brings to his tongue. Felix’s eyes shoot open with want at the presence of that single drop. He yanks his nails out, ignoring Sylvain’s groan of pain.

The Incubus admires the hunger in the Vampire as he watches him lick the blood clean from his fingertips. He can’t stop shaking in pleasure. Sylvain can feel the way his walls already want to milk him. It’s too good. He’s not going to let him leave. 

He grabs Felix, pulling him up against his chest and flipping them around in one swift, aggressive motion. Sylvain reclines, using his tail to hold Felix still as he pushes the protesting Vampire toward the crook of his neck and runs his other hand down the back of the pale torso, still comfortably ensconced in its length. It glistens in the moonlight peeking through the lifting fog as it pulses, enchanting enough not to be missed amongst all of the other undulations their bodies are providing in the rising tension. 

Felix latches on to his neck, biting down hard enough to break skin, running his tongue wide and firm over the impression. He does not clamp down to feed— not yet. He won’t settle and drink his fill until Sylvain is actually finished, but for now, he’s attempting to toy with him, forgetting that Sylvain is the one who set the rules of the game to begin with. 

Sylvain growls, pushing the head of the tail in a little deeper, wriggling and pulling back but not quite out. Felix disconnects from his neck with a gasp, craning in an attempt to look around and see the thick head of the appendage penetrating him. His walls clench tightly around the barbs, causing them to groan at the feeling of the texture together. Sylvain kneads his ass, pushing at him from both directions as if he could make them somehow meld together even closer— tighter.

“You feel good, Felix— _so fucking good._ You look so good like this. I want to keep you here, wrapped around me forever.” 

Felix rocks against him urgently, blood dribbling down his chin as he sucks in air like it’s the world’s fastest dwindling resource— moaning and basking in the light of all of Sylvain’s praises. His hips come in staggered juts as he pants, trying to move Sylvain’s tail deeper right where he really wants it. He groans in frustration when Sylvain remains still, letting him work his hardest on a task impossible to accomplish.

“Yeah? You need it that bad, Fe? Oh— you’re shaking, _Love_. Look at you, so beautiful, taking me like this— like it’s nothing at all.”

Felix’s fists curl around his shoulders as he growls and nips into his neck, tears hitting the back of his knuckles— visibly withholding a scream. It’s a wonderful sight that makes Sylvain coo and pet his hair. Felix curses at the tender touch harmlessly, twitching as Sylvain twists inside of him, edging just a little higher. It fills his heart with pride to see how broken Felix is already, just from his tail. He hasn’t even brought his cock out yet. He has no idea just how full he can— and will, be.

“Move— stop talking so much and just—! Fuck, Sylvain I’m going to lose my mind if you don’t fuck me!” 

His forehead is hot and sweaty, not enough blood remaining to give away the sign of a flush but Sylvain _knows_ that desperation anywhere. He’s teetering on the edge and all the Incubus needs now is to bring them both there. He slides his hand under Felix’s ass, past still trembling thighs, and presses a finger into him, slowly, carefully— listening to the beautiful sounds of Felix’s body accepting the additional intrusion, shuddering alongside his lover when he’s finally snug inside.

“Move? Is this what you want? You need more of me?” 

“Fuck.. _Fuck Sylvain,_ I can’t.. it’s too— ”

Sylvain slides easily— too quickly if he isn’t conscious to restrain it, and slips another finger inside to fit alongside his tail. Every pump sends more of Felix’s juices dribbling out to soak his thighs and stain deep into the mattress below. The sound is obscene— it’s all he can think about as the fingers of his other hand turn white from tension where they dig into the skin at the small of Felix’s back. 

“You’re so fucking _wet—_ how did you even..?” 

Felix grabs him suddenly and kisses him, crying into his mouth when he isn’t hissing and biting at his lips. He’s a mess, covered in spit and tears and blood, and the way that he clenches around Sylvain is enough to push his tail further still, curling and pulsating, until he meets the end of his resistance.

He chokes. A single, shaky, inhale and a scream roll through Felix before his eyes turn toward the back of his head as he comes. 

Sylvain pulls his hands back with a deep groan, nails elongating and darkening, his skin now a sleek purplish-red, chest expanding and ripping the front of his shirt. He retracts his tail—quickly—not wanting it to swell too much in the beginning while Felix is still adjusting to taking all of him, and licks up into his mouth to run his long pointed tongue across all of the sharpened teeth there.

“Damn it all to hell, Fe.” He breathes. “I can never get over how sweet you taste.”

“I hate sweets.” Felix grumbles— sounding sullen now that the high of his orgasm was wearing down. He tries to move, but only ends up wobbling back and forth like jello. Sylvain laughs and runs his hands down his back, steadying him.

“Vampires never did have very good taste.” 

“Hmmph.” Felix gnaws his frustration into the side of Sylvain’s neck, dragging his teeth down only just tenderly enough to manage to avoid breaking the skin. He stops when he reaches a place where the warmth is its greatest and laves his tongue over it, sucking instead.

“C’mon.” Sylvain groans. “Go on. I know you need it.”

Felix wrinkles his forehead, slanted amber jewels cutting straight through Sylvain under the shroud of the dark. He pulls back, kissing him once more on the now throbbing mark, before he sinks his teeth deep into Sylvain’s neck. 

“ _Felix_.”

It’s all he can say before he lets his head fall to the side, eyes lowered— giving in to the intoxication. Felix’s lips vibrating against his skin, warm, and soft, and swollen from his attention are better than any kiss he’s received. The soft little sighs and pleased hums that ring more momentous than wedding bells in his ears are enough to make Sylvain’s cock start to bulge from his pants. It’s been straining too long, bursting at the seams, and he needs to do something about it.

He pushes Felix up with one of his thickened arms, nuzzling his ass with his palm, while he reaches to unbutton them. A touch of instant relief makes him sigh, then sharply inhale at the feeling of the cool air and the firm pressure of his hand on his dick. He gives a few strokes, kissing Felix’s sweaty head and fitting his ass back toward it without interrupting his feeding. 

Felix hums a little louder, sensing what Sylvain is doing before he even feels the impression of his cock there. He relaxes, letting Sylvain’s tail wander as it pleases, pinching at his nipples, using the barbs to stimulate all the sensitive areas of his skin, slowly passing every one of his ribs and tickling by his ears. Sylvain continues to stroke, dipping his fingers into the wetness of Felix’s hole to keep himself lubricated. He’s still dripping, swollen, and eager to be filled. 

Sylvain leaves him to his feast, riding the feeling of lightheadedness. He starts to finger Felix open while he strokes his cock, restraining Felix to his spot with his tail. Two fingers were a breeze earlier, so he starts with three, breathing deeply in concentration. It’s gentle and intentional, and Felix is soon attempting to rock his body down onto it, clenching harder around him both on his neck and in his heat.

Sylvain tightens his restraints. “Take it slow, sweet. It’s not going anywhere, trust me. 

Felix pulls away from his neck with a gasp, licking the remainder of fresh blood off of his lips before diving in to lay claim to his mouth again. It’s aggressive and insistent, smearing their juices together and sending them dribbling down their chins. Sylvain breaks them apart to lick them up, shuddering and pulling his fingers away so he can rub the head of his cock against Felix’s entrance, combining those liquids as well.

“Think you’re ready to take me, love? How many have had the pleasure to fuck you like this?”

He doesn’t mean to ask the second question, frowning a little at the twinge in his heart. Curiosity shouldn’t feel this way. Felix is already his, and this is not the time to chase that truth. Expecting sarcasm, or some other caustic action, he stops his movements, creasing his brows and studying Felix’s reaction.

There isn’t much of one. Felix doesn’t often give things away by that manner of expression. He tells more through what he doesn’t do than by how he looks when he does, but now, he holds on to Sylvain, limp and shallow, tipping his eyes up to snag the hook in deep with the ghost of his smile.

“Only you.” He whispers, as if fidelity was supposed to remain a secret. “But yes, of course I’m ready. You’ve already kept me waiting.”

He grasps Sylvain’s cock in his slender hand, holding it there while he sinks down— patiently, despite his words. The girth is enough to make his knees attempt to turn in while he stumbles over little breaths. Every inch that envelops him sends Sylvain reeling back to the way he felt at the very beginning. Sylvain is used to the feeling of searing fire dancing under his skin, but compared to Felix’s glorious heat it is nothing. 

He kisses across Felix’s brow, murmuring encouragement among the smattering of filthy phrases. His tail releases, letting Felix’s body relax down against him. The tip of it snaps apart the hair tie hardly holding itself together at the ends. 

Felix smirks against his shoulder, taking him an additional inch. “Bastard.” He says, with no real vitriol. He can’t hide his shudder, however, when Sylvain strokes through his hair, pleased at the length, and pushes up just slightly to ease more into him. 

“You’re doing so well— so tight and wet for me. I want to take you apart and put you back together again, just for me. I want to fill you up, make you mine— as many times as it takes.”

The words are breathed into Felix’s face, hot and deep and authoritative. Sylvain’s hand wraps in Felix’s hair ensuring he cannot move away from them. The glow of his greed is illuminated further by the sudden shifting of clouds, allowing the moon to cast his features into sharp effect. 

“Empty promises.” Felix hisses, starting to lift and fall onto his cock, even though he’s only halfway seated. “Even for an Incubus, you spin too many sweet words. Should have been a Siren instead.”

He arches back, moving a little quicker, sinking lower, eyelashes fluttering, cheeks red as cherries and a healthy, full glow to his skin— shimmering like silver. Sylvain’s hands cup around his breasts, thumbs rubbing over hardened nipples, appreciating the change of view. Felix opens his eyes and parts his lips in a determined huff, looking like a painting of the gods with all the beauty of the world bowing behind him. Sylvain has to consciously remind himself to keep breathing and restrain from snapping his hips upward into him. 

His head cannot stop buzzing with palpable excitement. “You’re a sight for sore eyes, Doll.” 

Felix’s ears react to the comment, pushing back and to the side as he keens, trembling close to the base of Sylvain’s cock. He’s really doing so incredibly, opening up to him in a place that’s never been touched before, swallowing him as far as he can go. Sylvain’s hands fall to steady his hips, waiting while he tries to center himself, preparing for Sylvain to truly wreck him. The last bit always makes Felix so desperate— knowing what lies ahead. 

Felix shakes his head, groaning as he connects, falling forward to admit to the sheer volume of it. He presses down on the bottom of his stomach, quivering and constricting around Sylvain’s cock. Swaying slightly, he exhales high harmonies, and starts to settle in to control the position.

“Don’t rush.” Sylvain reminds him. He swipes his thumb across Felix’s mound and presses hard on his clit. Felix yelps, shifting in a circular motion on his cock and bucking forward into his touch. His eyes are glassy and beginning to look more desperate for release now that they’ve both fed. 

“I can make you feel good just like this.” The Incubus promises, stroking his hair and swollen nub at the same time. Felix shivers, leaning into Sylvain as close as he possibly can— leaving stifled noises against his collarbone to urge him along.

“Do you like that Fe?” He asks with a possessive growl that’s hardly any louder than the Vampire’s whimpers. His thumb presses harder— starting to circle in a slow, repetitive pattern. “Want me to make you feel good like this?” 

“ _Yes..._ ” Felix groans, grinding himself against the finger. “Not so slow…I— _Sylvain…_ ”

“I know…I know.” Sylvain assures him, picking up the pace. “Want to see you come so bad, Felix…Want to feel you pulse around my cock.”

Felix nips at his neck— trying to keep his mouth busy so he doesn’t let go of too many sounds that would alert Sylvain as to how good he’s making him feel— but the Incubus is fully aware. “You’re disgusting… _Ahh—_ don’t you ever run out of filthy things to say?”

Sylvain’s tail wraps around him again, and Felix reels in the anticipation of what is to come. The thumb is pulled away, much to Felix’s chagrin, but the sputter of a growing curse dies upon the contact of their foreheads meeting— raven and rust hair as entwined as the pounding of their hearts. 

“Never. Never with you, Fe. I’ll never run out of ways to tell you how much I love you.”

Felix flushes— hot enough to burn Sylvain’s cheeks from where they’re nearly pressed together.

“So many ways to tell you how beautiful you are, how amazing you taste, how I just want to hold you here forever— drinking from one another until our bodies burst.”

“Sylvain… _shit,_ I—”

Sylvain kisses him—devours him—nails digging deep into Felix’s back as the tail tightens and lifts his body up until there is enough room to slide most of his length out and back to fill him up again. It holds the Vampire perfectly in place while Sylvain starts to fuck up into him, lewd slapping echoing as he’s bounced higher. Felix’s head rolls back and to the side, mouth finally hung wide open. The noises now come like a torrent— _loud, urgent, unrestrained._ It’s the sexiest thing Sylvain has ever seen and all it makes him want to do is _give him more._

Tears roll down his cheeks and Sylvain almost stops, thinking he’s in pain, but Felix gasps out “ _Don’t you dare_ ” so he doesn’t— he merely wipes them away and buries himself deeper. Felix wails— wiggling without any accomplishment. Frustrated blotches of red decorate his skin.

“Tell me Felix.” Sylvain grunts, pressing his thumbs into the soft flesh by his navel. “Tell me who you belong to.” 

Felix whimpers and cracks one eye open, sucking drool back into his mouth as expertly as he can. His chest rises and falls faster than the speed of Sylvain’s thrusts. His hands ball into fists where they’ve been restrained at his side. Humiliated, he turns his face away with a hint of a pout and mutters something too low to be heard. Sylvain knows what it is, and Felix makes for such a pretty sight that he _could_ let it go, but he decides to goad him anyway. 

“I didn’t hear you.” He pulls Felix all the way down until their hips smack together again and leans in close enough to wrap his hand around the back of his neck. “Say it again. Tell me.”

“S-Sylvain...” Felix croaks. It’s as if he’s gone days without water and weeks without speaking another’s name. Sylvain kisses down his collarbone until he’s running his tongue over the sensitive buds of his chest. “ _Sylvain—_!” This time it’s a whine that would wake dogs with its intonation. It’s absolutely something Sylvain cannot bear to ignore. 

Sylvain grasps him tighter, the end of his tail curling around Felix’s shoulder to nudge against his cheek. Felix drops his jaw, turning to accept it and moans approvingly around the tip when it sinks in toward the back of his throat. 

“Oh good boy… so good for me. So eager. I didn’t even have to tell you...”

Felix takes him so perfectly. He’s grace suspended— eyes wider and deadlier than all the pits of hell erupting in unison. His body holds a glory that transcends the morning star. This here is the closest thing he has to a prayer. Sylvain does not confess to any god; he places his faith in love. There is nothing he would not trust Felix with. His body, his mind, all of his riches— whatever impression of a soul…

He pushes the hairs that have fallen forward to stick against Felix’s forehead and cheeks again out of range, returning to catch the moisture at the corners of his eyes and lips. His tail steadily sloshes against the pinpricks of Felix’s retracted canines— rocking inside of his mouth. 

“It’s undeniably wretched— what you do to me. Did you know that?” 

Felix sucks—hard—before spitting him out. Saliva gushes as he coughs, shuddering Sylvain’s name and clamping down tight around the cock inside of him. “ _Close..._ ” He manages to wrap his swollen lips around the single word, and it’s all he has to say, really. 

“Me too...” Sylvain whispers, and the tail loosens, pulling back to allow Felix to fall against his chest again. Fingers dance at his back entrance, both liberally soaked now with their juices. “Do you trust me?” 

Felix nods, small moans like the consistent hum of technology that vibrates with the cadence of his pulse. 

Sylvain circles the rim before pressing in slowly, finding no resistance. It slips past the knuckle before suddenly sliding the rest of the way, apparently eager to swallow him. He feels Felix smirk against his skin, shuffling back against his hand and urging a second finger to join in without issue. He’s already stretched and slick. 

“You devil.” Sylvain growls. “How cruel of you to keep such a secret from me.” 

He scissors the fingers a few times before deciding there was enough room to slip a third one in, slowing his thrusts on both ends to accommodate the addition. Knowing that Felix had done this, that he had prepared to take him in both his holes yet never mentioned it sent his mind reeling with the urge to fuck him senseless. What would Felix have done if he hadn’t claimed interest? Would he have begged him to fuck his ass open— only to laugh at the astonishment when he found him completely prepared?

“Put it in.” 

The three words come as an unexpected command— sudden and hasty. Sylvain’s nostrils flare at the weight of them. They hold too much influence for such a small and short vibration. He slips his fingers free, lining his tail up at the puckered hole— and _waits_.

“ _Sylvain.”_ Felix squirms to no avail, biting at his chest— smearing more tears across it. “Stop being such a bastard and _Put. It. In._ ”

The tail tickles at the sensitive flesh, rubbing under and back and forth with the lightest pressure Sylvain can manage, catching the juices that drip out of Felix’s pussy with every twist of Felix’s frustrated fists resting on his shoulders. Sylvain waits until he hears the height of the Vampire’s breathing hit that hiccup signaling the point of collapse, then sinks his own teeth in.

“If you insist.”

The sigh that Felix emits as Sylvain enters him is more breath than tone. His fists unclench, the nails of one hand finding purchase instead in the security of Sylvain’s neck. Felix leans back, flitting enough smoke from under the hood of his eyelashes to choke Sylvain, running the other hand down between their abdomens until his fingers stop on the bulge by his navel.

“ _Deep_.” He grunts, pressing down lightly and almost lurching forward again. He gasps a few times before slurring the next word. “ _Full_.” 

“ _Gorgeous.”_ Sylvain whispers back. “You look so good, Fe.” His hands trace the intricate patterns of Felix’s twisting back. “You’re so perfect like this— both holes filled, thinking only of me.”

“Only you.” Felix agrees, the echo reminding Sylvain of what he’d admitted earlier. Nobody else would dare touch Felix like this. This merciless creature of the night, immortal— _lethal. His. Felix was his._

“Keep going then.” He brushes Felix’s hair back into a rough, makeshift bun, held together in a single claw. “Take what you’ll have of me.”

Felix does not quite complete the sob that gurgles in his throat as Sylvain pushes a little deeper into his ass, barbs cementing him there. He shudders through a few more of them, dying between the bellows of his ribs, but living in the convulsion of his hips. The Vampire gradually gains more control until Sylvain is confident he can lay back, content with watching Felix use his body to get off, knowing that the moment Felix’s heat squeezes him in _just the right way_ he will follow.

“I can’t believe we’ve never done this before.” Sylvain can’t keep the honest statement from slipping out, not when Felix looks like this, neck arched to the side as he rises and falls and snaps his hips forward, leaving his slick behind as a mark of his devotion.

Felix’s hand curls in the ovular nest of hair where Sylvain still holds him, finding his fingers and extending his nails to scratch against the ends of the Incubus’ claw. “You never asked.” He strains, grinding his clit down, twitching inside and out.

“Can’t ask for what I don’t know exists, Fe.” Sylvain shifts, allowing Felix more access. His nails tap gently on Felix’s breasts, sliding over the nipples. Felix falters, pretending not to notice, scoffing instead as the hand in his hair grips a little harder.

“You definitely know this kind of body exists.” He sounds too solemn for someone riding an Incubus’ cock with his tail also buried deep in his ass, but Sylvain knows it’s a distraction— he can feel the true waver of Felix’s voice from where they are connected.

“ _Yeah_.” The tips of Sylvain’s claw travels up now, hooking into the front of Felix’s lip, pulling it down to look at how he withholds his pleasure. “But not on _you._ ”

A moan escapes, rolling down his wrist. _This_ is what Sylvain wants to hear. He releases Felix’s hair, letting the strands fall where they will. His fingertips rest in the hollow of Felix’s cheek when the Vampire takes his thumb into his mouth— _carefully_ —drawing it to the back of his throat.

Sylvain angles his hips upward, encouraging Felix to keep going, offering his own moan at how tight all three of Felix’s holes become around him in the rising desperation. “I wish you could see how incredible you look from where I am.”

Felix meets him in his shallow thrusts, pressing down on the head of Sylvain’s cock rubbing at the front of his stomach. “Shut up Syl-vain.” He scoffs, tongue pushing the thumb out of his mouth, but the way he breaks in the middle of the name gives his true feelings away.

“A vision.” Sylvain continues, unbothered by the way Felix is rubbing his clit against the low angle of his pelvis, antsy and greedy, still caught up in the rapture of watching him come undone through his praise. “All this for me? It must be my lucky night.”

Felix’s face is as ruddy as the Incubus’ skin, his body falling apart as if he were shredded by Sylvain’s claws, and yet, he cannot let go without having the final word— wanting to preserve some semblance of dignity. 

“It’ll be your last night if you don’t…make me come before dawn...” 

He stops, conserving the last vestige of vitality, glittering face adorned with sweat and the violet hues of the encroaching sunrise. 

“Sylvain… _Please_.”

Sylvain sits, drawing Felix’s legs around his waist, rocking him slowly— forehead to forehead. In all of their trysts, few have ended as intimate as this. Golden rays leak through the window panes to smile across the high, angled planes of Felix’s face. The spots Sylvain gains as a consequence of watching the light enshroud him—unblinking—merely add to his beauty, dusting dappled secrets over the delicate vessels of his eyelids. The circular pattern of their breath, heavy and unfiltered, tastes to him only of Felix. 

“Come on baby… Felix, let go for me.”

Felix makes no noise when he comes this time; he hardly gives indication at all. If it were not for the impossibly tight refuge of his walls that throb around him, Sylvain would have needed to rely on his baser instincts to determine the end. The Vampire only twitches once, when Sylvain tries to pull away to finish outside of him, locking his legs and extending nails once again into the Incubus’ back where he clings like a gloomy koala. 

“Stay.” He murmurs sleepily, smearing the syrup of the word where he noses into Sylvain’s neck.

Sylvain has no time to consider another option, already spilling from where he’s pressed deep into Felix’s stomach. All of the heat in his own gut overflows to blanket Felix’s insides, leaving them warm and full where they are connected. 

Felix sighs, as if a great weight has been subtracted instead of added. He settles quietly, accepting Sylvain’s decision to pull him down to rest on top of his chest without argument. The chirping of birds is impressively loud in the absence of their usual banter. They remain still, one of Sylvain’s hands working the knots from Felix’s hair patiently, while the Incubus waits for whatever Felix was restraining himself from sharing.

“I never told you, did I? What I really am?”

 _Ah, this._ Well, it never came up, but Sylvain had known for a long time. Now was as good a moment as any to talk about it, seeing as Felix had come to him revealing two of his alternate forms. 

“Miklos.” Sylvain shrugs, wrapping his arms around Felix all the more. Felix tenses, and Sylvain senses the return of the divide they’d spent too many years dancing around instead of crossing. He’s not going to let that happen, not after tonight. Not after he’d finally broken beyond Felix’s walls— got him to the point of even saying _please_. 

“It doesn’t matter.” He insists, pressing a kiss to the crown of Felix’s drenched head. _Gross. We should shower soon._ “You’re still Felix to me. _My_ Felix. Always.”

“I belong to myself.” Felix grumbles, but there’s a shade of pink in his cheeks that the shifting sunrise isn’t responsible for. Sylvain waits an additional minute to continue, trying to calm his heart from the anticipation of what he’s wanted to ask for going on hundreds of years. 

“Stay with me. Just for one more day. Please?” 

He’s almost immediately convinced he’s made a mistake, but the gamble had to be taken. Sylvain didn’t want to bring it up while Felix was here and he could push it to the back of his mind, but this last separation had almost destroyed him. He’d missed Felix too much. A single day wasn’t nearly enough, but he only really needed a few seconds to retrieve the ring he’d kept safe in his nightstand drawer. Perhaps one day could turn into another, and that day into another again, until he was certain there was enough time to resize it to fit Felix’s true form. 

He opens his mouth on impulse, unsure of whether he aimed to apologize or further plead. Felix halts it with a finger, raising his head a few inches to meet Sylvain’s surveillance before he gives his answer. 

“One more day.” The Miklos nods, like he’s considering something grave. The mischievous gleam of his eyes holds all the confessions Sylvain will ever need to see. “Good thing you don’t keep a calendar.” 

**Author's Note:**

> I am on [twitter](http://twitter.com/thefriedpipes)! Come talk more about fe3h with me 🤗


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